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Surviving the coronavirus, then testing positive again
- rossdavidh 7y agoMaybe because the false-positive rate for asymptomatic patients is estimated at 80%?
- elliekelly 7y agoDo you have a source for this information? This is the first I've heard of false-positives.
- ryanburk 7y agosource??
- numpad0 7y agoFalse positive? I’ve heard although false negatives(contracted but asymptomatic) can be up to 40-60%, but RT-PCR is reliable at declaring positives.
- whoisjuan 7y agoThere's a possibility for false-positives. I think there's a type of test that looks for an enzyme that you could have without contracting the virus. I saw an article in HN this morning, but I can't find it anymore. Also, false positives could happen as a result of bad logistics and management of the specimens. Some useful sources that seem to validate the occurrence of false positives: - This research on testing specifically calls out the fact that their method didn't yield false positives in trials: https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2020.25.3.2000045 https://www.eurosurveillance.org/content/10.2807/1560-7917.E..., which seems to indicate that it's common for false positives to occur when developing testing methods for new viruses. - This research talks about false positives in asymptomatic patients: https://www.ncbi.nlm.nih.gov/pubmed/32133832 https://www.ncbi.nlm.nih.gov/pubmed/32133832. "In the close contacts of COVID-19 patients, nearly half or even more of the 'asymptomatic infected individuals' reported in the active nucleic acid test screening might be false positives." - This guy in Egypt is apparently a false-positive, likely due to a mismanaged testing protocol: https://www.livescience.com/matt-swider-stuck-in-egypt-coronavirus-quarantine.html https://www.livescience.com/matt-swider-stuck-in-egypt-coron...
- Vesuvium 7y agoI imagine with many tests, even at 0.1% eventually you'll get some false positive due to human error, or other things going wrong
- LeifCarrotson 7y agoThe false positive rate is nowhere near 80%. All positive test results - both false and true - are at less than 5%. 80% might be the probability that an asymptomatic patient who tests positive is actually clear, but that's not what the statistic "false positive rate" means.
- rossdavidh 7y agoThe term "false positive" is the one used in the NIH-linked article: "Potential false-positive rate among the 'asymptomatic infected individuals' in close contacts of COVID-19 patients" https://www.ncbi.nlm.nih.gov/pubmed/32133832 https://www.ncbi.nlm.nih.gov/pubmed/32133832
- deleted 7y ago[deleted]
- virusduck 7y agoThis isn't an NIH-affiliated article, to be clear. It's from a Chinese set of authors on a Chinese journal. But, it's not, because the article is now nonexistent. http://rs.yiigle.com/yufabiao/1183773.htm http://rs.yiigle.com/yufabiao/1183773.htm
- djaychela 7y agoHeard something about this on one of Sam Harris' two podcasts on the subject this week - that this is typically because of a false negative test (indicating recovery from the virus) during what in reality is a longer, uninterrupted period of infection.
- taeric 7y agoPlease be crisp on this. That is one hypothesis, but do we have the data yet to make sure it is the answer? I'm doubtful. Could also be unknown recall rates on the test. Could be plenty of things.
- xeromal 7y agoWhat does crisp mean in this context.
- tomrod 7y agoExact quotes and precise figures. Gives the intellectual "crunch" in an arena with lots of speculation.
- taeric 7y agoI am just meaning to be clear and not to stretch claims beyond what we know. So, for example, I have a hypothesis that this is mainly baseline lung damage causing severe cases. That said, I cannot claim that is what it is. I'm sure I have been sloppy and pushed this idea some without being clear it is just a hypothesis of mine. That said, I try and be clear with that message.
- cblades 7y ago"mainly baseline lung damage" could you expand on what you mean there?
- taeric 7y agoCopying from https://news.ycombinator.com/item?id=22562362 https://news.ycombinator.com/item?id=22562362 The part of Italy hit also has air quality, per aqi searches, that is comparable to the region in China that was hit hard. Have people looked that it is not age, but baseline damage to your lungs that is the main factor in serious cases? Older people will have more exposure to local air pollution, just from having lived longer. That existing damage can be what contributes to complications, right?
- irjustin 7y agoI really hope it's simply poor diagnosis. It appears to be, so it's not yet time to be scared. But, if the virus is capable of mutating at the rate of the common cold and reinfect - I see no way out from under this other than a new way of life.
- _bxg1 7y agoSeeing as China's condition seems to be improving, instead of having cases just keep burning indefinitely, I doubt that's the case.
- ceejayoz 7y agoChina's still in lockdown, though, which would be that "new way of life" (until a vaccine) if re-infection is common.
- _bxg1 7y agoNot completely: https://www.theverge.com/2020/3/13/21177964/apple-stores-china-reopened-coronavirus-covid-19 https://www.theverge.com/2020/3/13/21177964/apple-stores-chi... They aren't done with the virus, but the worst seems to be past. Whereas if it could easily re-infect then I would expect the case numbers to strictly increase.
- soperj 7y agoDoes it even need to re-infect? They had 80 thousand cases in a country of over a billion.
- deleted 7y ago[deleted]
- malandrew 7y agoI'm wondering if China is shooting itself in the foot by being on lockdown because they may just be delaying the inevitable now that it's pandemic and at risk of becoming endemic. If we assume this will become endemic and a vaccine is a ways off, it would seem like the best approach is to flatten the curve just under the healthcare system capacity and get it to "pass through" most of society quickly (i.e. everyone who is at lower risk gets infected and quarantines until viral shedding stops). Doing this would allow us to return the economy back to normal as quickly as possible and prevent all the fallout from an indefinitely stopped economy. Once most people have had it, we'll essentially end up in a state of herd immunity and it becomes statistically less likely than other health concerns at-risk populations had before COVID-19 was even a thing. Meanwhile China, being on lockdown the entire time is still susceptible to having it become a pandemic within their own population as soon as they lift the lockdown and try to return to normal because they citizens haven't had the opportunity to develop antibodies as broadly.
- newfeatureok 7y agoThere are some questions I haven't been able to find good answers to in addition to the one posed in the article: 1. Is it possible to get COVID-19 twice? 2. If (1) is true, are the symptoms the same (if applicable)? 3. If (1) is true are you still contagious? 4. There's evidence that there are multiple strains, can you get both strains? 5. What's the likelihood that a mutation will occur once treatment is more widespread? 6. Does the heat make it significantly less likely for you to get COVID-19? My impression so far is that we'll never get rid of this thing, and at best this will be something like the seasonal flu, where we'll just have to live with it and great shots yearly.
- coliveira 7y agoYou will not find concrete answers online because this is a research area, scientists are not sure yet about how to answer these questions. And sometimes the existing answers are based on limited information or just misinformation.
- fendy3002 7y agoAnd this disease is still very new. There are too many unique cases and difference between cases that it's almost impossible to take any conclusion.
- leesec 7y ago1. Is it possible to get COVID-19 twice? No, doesn't seem to be, but you might still have "viral shedding" for a bit even after you are "recovered". meaning you could still be contagious. 4. There's evidence that there are multiple strains, can you get both strains? You shouldn't think about them as multiple strains, as of now it is 1 disease. 5. What's the likelihood that a mutation will occur once treatment is more widespread? Mutations occur all the time, there are already 10's of known mutations of virus, it doesn't mean there are 10 separate diseases. 6. Does the heat make it significantly less likely for you to get COVID-19? There's some evidence warm weather slows spread for viruses like this, but we can't assume that about this virus yet. A good counterpoint is Qatar adding 258 cases in one day, it's hot there.
- gazelle21 7y agoIs it not possible the test was faulty? It seems like the most simple explanation.
- numpad0 7y agoThe article doesn’t say whether the status of survivors are declining or not, only that they remain positive.
- koheripbal 7y agosome, not all.
- codeulike 7y agoA slightly more informed article on huffpost: "Can You Get Coronavirus Again After You've Already Had It?" https://www.huffingtonpost.co.uk/entry/can-you-get-coronavirus-again-after_l_5e6a8e2fc5b6dda30fc57d7d https://www.huffingtonpost.co.uk/entry/can-you-get-coronavir... Edit: Also, Fortune: "Why are patients who recover from coronavirus testing positive again?" https://fortune.com/2020/03/06/coronavirus-recover-test-positive-twice/ https://fortune.com/2020/03/06/coronavirus-recover-test-posi...
- jostmey 7y agoI did some reading on coronaviruses and learned these viruses do not have reverse transcriptase, which would allow an RNA virus, like a coronavirus, to incorporate into the host genome, becoming a permanent resident. In other words, the viruses lack the machinery necessary to convert themselves into DNA and cannot cause a chronic infection. That said, it is possible that people co-infected with another RNA virus expressing reverse transcriptase would allow the coronavirus to incorporate into the host genome
- jimmytucson 7y agoGiven it's flu season right now, is flu an RNA virus and is there a high risk of co-infection?
- globular-toast 7y agoInfluenza is not a retrovirus either. Retroviruses include HIV and are the most beautiful viruses of all.
- MegaButts 7y ago> Retroviruses include HIV and are the most beautiful viruses of all. I honestly do not know what you mean by this. Can you please elaborate?
- globular-toast 7y agoIt's hard to appreciate without first understanding how our genetics work. That is, the mechanisms that are responsible for replicating our genomes and turning our genes into proteins. Viruses are an inevitability because they exploit vulnerabilities in those mechanisms. Viruses are not alive. Instead a virus causes "live" modifications to a living organism which causes it to simply reproduce more of the virus. When you have a virus you are essentially one with the virus; a modified organism. Retroviruses go one step further by permanently making that modification. Now you are forever modified with the extra functionality of producing more of that virus. But the really beautiful thing is how minimal these viruses are. If you've played code golf you'll appreciate it. In the smaller RNA viruses like influenza and HIV, each virion carries around exactly what it needs to make those modifications and not much more. They consist of proteins which cause our cells to accept them as well as the genome which causes our cells to make more of those proteins. They also cause our cells to reproduce the genome itself too. Eventually the cells become full of virus stuff and somehow the viruses assemble themselves back into virion, the cell dies and releases the new virions. The HIV genome is incredibly compact. It's the closest thing to design I've ever seen in biology. It packs more information into its genome than would normally be possible by utilising overlapping genes on the forward and reverse strand. It's quite remarkable just how clever, minimal and perfect it is.
- sandGorgon 7y agoThis is a very weird article. I'm not sure if its just an old article that got recently republished. Because the latest research shows that there are two strains of COVID and reinfections are happening because of the other strain infecting you. https://academic.oup.com/nsr/advance-article/doi/10.1093/nsr/nwaa036/5775463 https://academic.oup.com/nsr/advance-article/doi/10.1093/nsr... https://www.cnbc.com/2020/03/04/coronavirus-chinese-scientists-identify-two-types-covid-19.html https://www.cnbc.com/2020/03/04/coronavirus-chinese-scientis...
- allemagne 7y agoI can't find where in those links it supports the claim that "reinfections are happening because of the other strain infecting you"
- koheripbal 7y agoThere are not two strains - that turned out to be bogus.
- strategarius 7y agoThere are many cases of "false negative" with current testing kit. Most probably, patient who almost recovered, received false negative result and has been released from quarantine still being contagious. Partying with neighbors definitely was a bad idea.
- sbmthakur 7y agoThere are case(s) in India where potential patient(s) got around thermal scans by consuming paracetamol that suppressed their fevers.
- tannerbrockwell 7y agoThe tests are not accurate. [1] We are running around like chickens freaking out about tests. The only thing to do at this point is Social Distancing so the growth curve flattens out. Testing is NOT a solution. Testing will not make a sick person better. We have limited resources. Testing is being advocated by those trying to trace the community spread. I have news for you, if you think you have it you got it! Everyone will get it. Tracking this is a waste of resources at this point as the false positives mean additional limited Frontline Health Care workers treating actually sick individuals. We need to minimize the community spread, that means stay away from events. Work from home. Individuals should self quarantine at any sign of illness. Critical patients should be admitted to hospitals. Everyone else should do everything in their power to slow the spread. You got a cough? Stay home. You feel tired or run down? Stay home. You have a fever and it went away? Stay home for the next 14 days. If your employer will not let you work from home, email them that you believe you are an asymptotic carrier of the COVID-19 virus and if they will not let you take paid sick leave or work from home you will be in the office immediately. Tell all your coworkers you requested to stay home and management wouldn't let you... Let the lawyers sort it out with HR. [1]: https://www.ncbi.nlm.nih.gov/pubmed/32133832 https://www.ncbi.nlm.nih.gov/pubmed/32133832
- BubRoss 7y ago> I have news for you, if you think you have it you got it This is a ridiculous thing to say after talking about test accuracy. You can't improve what you can't quantify. Also your assumption that so many people have a job they can do from home or over email is ridiculous.
- altcognito 7y agoIn fact, you won’t know if your test is inaccurate if you don’t test! Over and over again I hear people talk about how it is a waste of resources to test. Tests are not expensive in time or material. They will pay off. No, they don’t help you cure anything. We dont have a cure! Tests help you quarantine and mitigate.
- ajuc 7y ago> You can't improve what you can't quantify. That's obviously false.
- Ahmed90 7y agoDr. Vincent Racaniello was a guest on a Twitch.tv podcast hosted by Ethan Evans (Amazon VP) and Devin Nash (CMO @N3RDFUSION) They talked for 2 hours and pretty much covered a bunch of questions about this subject, there is so much misinformation and panic going around Here is a youtube link if anyone is interested @ https://www.youtube.com/watch?v=WWNuDT4t-TM https://www.youtube.com/watch?v=WWNuDT4t-TM Also a Pastebin with the highlights https://pastebin.com/8juyjNFq https://pastebin.com/8juyjNFq --- Dr. Vincent Racaniello, Ph.D. (@profvrr on twitter) is Higgins Professor of Microbiology & Immunology at Columbia University Medical Center. He has been studying viruses for over 40 years.
- pmoriarty 7y agoDr Racaniello is also the host of the This Week in Virology podcast, which I highly recommend. They've had a series of episodes on COVID-19 recently, all highly informative. Episode 590, the most recent one, debunked the "two strains" rumor that's been going around. You can hear the episode here: [1] and read a transcript of the portion of the episode where the rumor was debunked here: [2] [1] - http://www.microbe.tv/twiv/twiv-590/ http://www.microbe.tv/twiv/twiv-590/ [2] - https://news.ycombinator.com/item?id=22564199 https://news.ycombinator.com/item?id=22564199
- Ahmed90 7y agoYep
- DiogenesKynikos 7y agoThese tests test for the presence of viral nucleic acid. You can still have detectable levels of viral nucleic acid in you after the infection has ended. What actually matters is whether or not you have virus replicating in you. The presence of viral nucleic acid is an imperfect proxy for that.
- chiefalchemist 7y agoMy understanding is PCR doesn't actually test for the virus itself. It tests for antibodies. Such that, once you get a virus and have antibodies, you have them for life. The idea of getting it twice seems odd.
- refurb 7y agoCan't access the article, but PCR = polymerase chain reaction and is a method for amplifying DNA so you can actually analyze it.
- jhayward 7y agoNo, PCR is not an antibody test. It amplifies DNA or RNA sequences which are known to exist in the virus. If enough unique sequences are found the test is positive.
- chiefalchemist 7y agoRight. Thanks for clarifying. To clarify further, it doesn't actually test for the virus. It tests for DNA / RNA presence. It's a proxy. Not being critical, etc. Simply nailing down loose ends.
- jhayward 7y ago> it doesn't actually test for the virus. It tests for DNA / RNA presence The virus is nothing but DNA or RNA. The snippet testing establishes a statistical baseline that rules in the presence of the specific dna/rna of the virus to within the required certainty. In other words, you don't have to feel every inch of an elephant to know for sure you've got a hold of one. Just enough features to make it unique to just elephants.
- sudosysgen 7y agoNo, PCR test for a given RNA or DNA block. It will detect the virus, it will detect dead viruses, it will detect neutralized viruses, and it will detect virus bits.
- allovernow 7y agoIf you can get reinfected, there's a good chance that the second infection will have a particularly high mortality rate, because this virus likely has a property known as antibody dependent enhancement[1]. Long story short, your normally protective antibodies actually work for the infection. This was a property of past coronaviruses like SARS and is likely why no vaccine was successfully developed. 1.https://www.sciencedirect.com/science/article/pii/S1286457920300344 https://www.sciencedirect.com/science/article/pii/S128645792...
- sashaafm 7y agoThat means the population overall may build immunity to it?
- allovernow 7y agoWell, not exactly, it means that "immunity" may actually be dangerous or fatal. Because immunity implies release of antibodies on re-exposure, except in this case the antibodies bind to the virus, as normal, but then the virus infects much more readily, prompting the body to produce more antibodies and mount an ever greater immune response in a dangerous cycle.
- mensetmanusman 7y agoIf there is a 20+% false positive/negative rate, then there are many people this will happen to.
- KCUOJJQJ 7y agoCan someone tell me if the virus could be persistent? The virus is related to chickenpox according to [0]. And according to [1] "Once chickenpox has resolved, the virus may remain inactive in nerve cells." Risk factors for shingles are: "Old age, poor immune function, having had chickenpox before 18 months of age". [0] https://www.osha.gov/SLTC/covid-19/medicalinformation.html https://www.osha.gov/SLTC/covid-19/medicalinformation.html [1] https://en.wikipedia.org/wiki/Shingles https://en.wikipedia.org/wiki/Shingles
- tannerbrockwell 7y agoI warned you a week ago we would "waste of resources" and here we are: "Health officials are struggling with a complicated message — more people can get tested, but those with mild symptoms should stay home and practice social distancing. Some go so far as to warn that widespread testing at this point could threaten the U.S. response by burning through precious supplies just as a tidal wave of sick people descend on the system — a message at odds with administration announcements that millions of test kits are finally becoming available." [1]: https://www.washingtonpost.com/health/2020/03/21/coronavirus-testing-strategyshift/ https://www.washingtonpost.com/health/2020/03/21/coronavirus...